A plummeting Portsmouth are on top of the world. After such a transformation no one can scoff at the mystique of the FA Cup. The victors in this semi-final are still pitiable for the relegation confirmed on Saturday and the fact that they will not be taking their place in the Europa League. That prize would normally be theirs since their opponents, Chelsea, already have a berth in the Champions League, but Portsmouth, now in administration, knew it would be futile to seek the Uefa licence required.

Nonetheless, there is no tinge of sorrow for Avram Grant's side, who have the astonishing opportunity to take this trophy on 15 May. Portsmouth, of course, won the FA Cup in 2008 and the feat hurtled the club further into unsustainable expense. There will be no exorbitance in the Championship next season. Tonight, however, nobody was thinking of shrinking horizons or the shrivelled budgets that make most of the current squad unaffordable.

Tottenham Hotspur dominated and Peter Crouch, in particular, will be incredulous that he did not score. The striker, of course, used to be on the books at Fratton Park. There are many ties between these clubs and it often looked as if the sides would never disentangle themselves.

It took the referee to keep them apart even after Portsmouth had gone into the lead. Within moments of the goal, Alan Wiley wrongly disallowed an equaliser by Crouch from a Gareth Bale cross when he supposed there had been by a foul by Niko Kranjcar on David James. A curse was probably essential to deny Harry Redknapp's side. Even the opener depended on the random conduct of a pitch at Wembley that is already notorious.

Nine minutes into extra time, a Marc Wilson set-piece came off the head of Kevin-Prince Boateng and would have been attended to had Michael Dawson not lost his footing. The centre-half fell and Frédéric Piquionne pounced, shooting beyond Heurelho Gomes. A wretched day for Redknapp's team concluded when Portsmouth scored again three minutes from the end. Wilson Palacios brought down Aruna Dindane and Boateng, one of a several former Tottenham players, converted the penalty.

Redknapp himself, of course, had guided Portsmouth to the success in this competition two years ago. This was an indifferent match for much of the time. While the FA has responsibility for the whole of English football, egalitarianism has gone too far at Wembley. The pitch is of such poor quality that it could make any pair of teams look like equals.

With the drop from the Premier League already confirmed, it felt as if Portsmouth had risen from the crypt to take part in this semi-final. The squad relished its role as the undead and left Tottenham with a shudder that will be relived whenever they recall this loss. Redknapp's men were afflicted by bad luck, but they also exasperated themselves.

The hour mark had not quiet been reached when Jermain Defoe was removed, presumably in a fit of managerial exasperation. That must have heartened Grant's side. Portsmouth, also enjoying the passionate backing of supporters who had taken a day off from dejection, showed plenty of purpose throughout. They enjoyed the best opportunity before the interval, when Hassan Yebda broke in the 37th minute and fed Piquionne, only for the striker to shoot straight at the goalkeeper Gomes.

The Frenchman was set up again, by Dindane after 56 minutes, and once more allowed an easy save. Tottenham, with a superior squad, still had the better of it. They showed menace, even if they could not capitalise, and James, for instance, had to produce a particularly impressive save to reach an excellent left-footed attempt from Tom Huddlestone in the 39th minute. At times each team was hindered by the unpredictability of the poor pitch, but Tottenham eventually achieved what was to be a misleading authority.

James was fortunate when he failed to collect a David Bentley corner in the 65th minute and saw Crouch nod the ball wide of the target. Eleven minutes later, another header from the Tottenham striker clipped the outside of the post as he tried to direct Gareth Bale's deep delivery back into the middle.

Crouch was on verge of a winner in second-half stoppage time when he connected at the near post with a low ball from Kranjcar, only to watch his finish bounce back off the legs of James. Resolute Portsmouth ensured that there was always an insurmountable barrier for Tottenham.